getBluetoothService called with no BluetoothManagerCallback

Question

I am getting getBluetoothService() called with no BluetoothManagerCallback as an error frequently in my Android application.

I have no idea what is causing this or anything about bluetooth manager callbacks. Can anyone give me a good idea of what could be causing this problem or where to start looking.

Answer 1

By reading into the Android source code, it seems to be a warning you cannot do anything about. The source code shows that if you call

BluetoothSocket#connect(); 

Then it will call

BluetoothAdapter.getDefaultAdapter().getBluetoothService(null); 

The key here, is the null parameter that it passes in the above line. Due to this, there will be no callback, and then the BluetoothSocket class will throw out a warning.

Since it is only a warning, I do not think you need to do anything about it.

https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/bluetooth/BluetoothSocket.java line 306 https://android.googlesource.com/platform/frameworks/base/+/master/core/java/android/bluetooth/BluetoothAdapter.java line 1610

Answer 2

It appears that this gets called when multiple bluetooth sockets are opened at once. I fixed this by ensuring I was only opening 1 socket at a time.